メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.4375000 43.8625000, 142.4437500 43.8625000, 142.4437500 43.8666667, 142.4375000 43.8666667, 142.4375000 43.8625000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral